1. Field of the Invention
The present invention relates to an apparatus for recording and reproducing digital data and a method for the same, and more particularly to an apparatus for recording blocked digital data on a magnetic tape and a method for the same.
2. Description of the Related Art
In recent years, various kinds of apparatuses for recording and reproducing digital data have been widely applied with the advancement of the technology for recording and reproducing digital data. As a record medium, a hard disk, an optical disk, a magnetic tape, and the like are used. Among them, the magnetic tape is more practical and superior in storage capacity, changeability, and price (in a unit cost of capacity), compared with other record media.
Data to be recorded on a magnetic tape is mainly classified into two kinds of data: data transferred and recorded by a host such as a computer and data automatically added (additional data) by an apparatus for recording and reproducing. The additional data includes information concerning a leading edge and a trailing edge of a recording region on a magnetic tape, information concerning the delimitation of blocks formed therein, an address indicating the position therein, information for error detection or error correction, etc. It is convenient for the host to utilize information concerning a name, an attribute, a size, and the like of data during recording, reading, or searching for the data. Such information is referred to as management data in the present specification.
The data transferred by the host is recorded after being divided into blocks having a predetermined size. For example, in the case of a usual computer, the data is divided so as to have 512 bytes per block. Each block is the minimum unit of the magnetic tape in which data can be recorded. Data divided into a predetermined size by the host is referred to as blocked data (herein, blocked data means a xe2x80x9cblocked dataxe2x80x9d unit or xe2x80x9cdata blockxe2x80x9d). Thus, the blocked data becomes the minimum unit for recording on the magnetic tape. Furthermore, instructions (marks) for searching data can be recorded on the magnetic tape. The blocked data and marks can be recorded with respective numbers assigned thereto.
Some blocked data can be combined to be recorded as grouped data (herein, grouped data means a xe2x80x9cgrouped dataxe2x80x9d unit or xe2x80x9cdata groupxe2x80x9d). FIG. 34 shows an example of grouped data recorded by a conventional apparatus for recording and reproducing digital data. This example shows a DDS format using a digital audio tape-recorder (DAT). One group of the grouped data include 126632 bytes. Each blocked data is arranged from the leading edge of the grouped data.
Information concerning the grouped data (management data) G is positioned in a group information table placed in 32 bytes of the trailing region of the grouped data. Information concerning each blocked data (management data) B1, B2, . . . indicating the size and the like of each blocked data are arranged in the direction from a portion right before the group information table to the leading edge of the grouped data. The information B1, B2, . . . concerning each blocked data respectively have a fixed length.
In the DDS format, data is recorded and reproduced as follows:
In a random access recording and reproducing apparatus, by designating the number assigned to each block (i.e., absolute addressing), data corresponding to the block with that number assigned can be read or recorded. Likewise, by absolutely addressing the number assigned to each mark, data can be reproduced from the position of the mark with that number assigned.
In a sequential recording and reproducing apparatus which does not perform random access, data is recorded in the order in which the blocks are arranged or in a predetermined order. Likewise, data is read in the order in which the blocks are recorded. In the sequential recording and reproducing apparatus, the position of the recorded blocks is relatively addressed (for example, a block following four blocks after a certain block).
As described above, data is recorded or read by relatively or absolutely addressing a block.
Hereinafter, a searching method in a conventional DDS format will be described.
FIG. 35 schematically shows grouped data in the conventional DDS format. As shown in this figure, the number of a block whose recording is first started in a group and the number of blocks whose recording is started in the group are recorded in a subcode region on a group basis. The block No. is represented by g, and the number of the blocks is represented by m. Hereinafter, simply referred to as numbers g and m. The subcode region is a region of the track where data can be reproduced even during searching.
When the numbers g and m are obtained for a group during searching, it is found that the recording of the blocks with the numbers g to g+mxe2x88x921 is started in the group. By using this, the group in which the recording of a desired group is started is found, and a desired block is reproduced. Likewise, the number h (h1 in the figure) of a mark whose recording is first started in a group and the number k of marks whose recording is started in the group are recorded in the subcode region of the group. In the case where the numbers h and k are obtained for a certain group during searching, it is found that the recording of the marks with the numbers h to h+kxe2x88x921 is started in the group. By using this, the group in which the recording of a desired mark is started is found, and a desired block in a position designated by the mark can be reproduced. Alternatively, data searching can be conducted by recording, in the subcode region, the number of a block whose recording is first started in a group and the number of a block whose recording is last started in the group.
FIGS. 36A to 36D show the patterns of track groups recorded in the conventional DDS format. A magnetic tape runs in the direction indicated by an arrow in FIG. 36A. Grouped data to be recorded is subjected to a predetermined signal processing to form a data track group D1. As shown in FIG. 36B, the data track group D1 is recorded on the magnetic tape together with amble track groups A positioned before and behind the data track group D1 (i.e., a preamble track group and a postamble track group) and a data end track group E.
Overwriting of data is conducted as follows:
First, the data end track group E is searched to detect the last-recorded position. Then, recording of data is started from the trailing edge of the postamble track group A positioned before the data end track group E. As a result, the data end track group E which has been recorded is deleted and only a latest-recorded data end track group E is left on the magnetic tape. FIG. 36D shows the pattern of track groups in which data track groups D2 to D4 shown in FIG. 36C are recorded in addition to the data track group D1.
In order to prevent a data track group from being positioned right before the track at which the additional recording is started, the previously recorded postamble track group A is left on the magnetic tape. The reason for this is that the track, right before the track at which the additional recording is started, has its width cut away by the additional recording, increasing the frequency of error occurrence.
Furthermore, as shown in FIG. 37A, in the conventional DDS format, information concerning the entire magnetic tape (tape management data) is recorded in a system area positioned in a leading region of the magnetic tape. In the DDS format, one or two data regions called a partition can be assigned on the magnetic tape for convenience of data management.
The leading region of each partition is assigned as a system area corresponding to the partition, and information concerning the use record of the partition (i.e., system log) is recorded in a subcode region of the system area (see FIG. 37B). Data is recorded with a fixed-length in the subcode region. In the case where one partition is assigned on the magnetic tape, the contents of the system log of the partition becomes equal to that of the entire magnetic tape. In the case where a first partition and a second partition are assigned on the magnetic tape in the order of the tape running direction, information concerning the use record of the entire magnetic tape and information concerning the size of the first partition are recorded in the system log of the first partition; and information concerning the second partition is recorded in the system log of the second partition.
Each partition is identified as follows:
In the case where one partition is assigned on the magnetic tape, the partition number is set at 0. In the case where two partitions are assigned on the magnetic tape, the first partition number of the leading side partition of the magnetic tape is set at 1 and the second partition number of the trailing side partition of the magnetic tape is set at 0. When a cassette is loaded, the first partition number is checked to obtain the number of partitions.
However, in the above-mentioned DDS format, information concerning blocked data (management data) is recorded in a fixed-length form, so that the management data for blocked data which requires less information (for example, without attribute information has the same length as that of the other blocked data). This results in decreased recording efficiency.
Moreover, in the conventional DDS format, two kinds of informations (g and m, and/or k and h) are required to be recorded per group for searching data. For accessing a desired block, it is required to search, reproduce, and perform an operation on two kinds of information, and to compare the result with the desired block (or mark) number. Thus, a large subcode region for recording two kinds of information for searching as well as an additional circuit and time for the operation are required.
In addition, for overwriting data in the conventional DDS format, the additional recording is started with the previously recorded postamble track left on the magnetic tape; therefore, the postamble track group and a preamble track group are present between the previously recorded data track group and the latest-recorded data track group. As the number of ample track groups increases, the data capacity of one magnetic tape decreases.
Furthermore, as described above, in the case where two partitions are assigned as a recording region on the magnetic tape, the system log of the second partition is required to be reproduced for obtaining information concerning the second partition. In this case, time is required for reproducing two different system logs, making it impossible to search data between different partitions at a high velocity.
The apparatus for recording and reproducing digital data of the present invention, comprises:
group conversion means for receiving input blocked data, arranging the blocked data in a predetermined order to generate grouped data, and outputting the grouped data;
control means for receiving a command input together with the input blocked data and generating a control signal and management data based on the command;
recording conversion means for receiving the grouped data and converting the grouped data into a recording signal based on the control signal;
recording means for receiving the recording signal and recording data represented by the recording signal on a record medium;
reproducing means for reproducing from the record medium a signal representing the data recorded in the record medium;
reproducing conversion means for receiving the reproduced signal and converting the reproduced signal into grouped data; and
group reverse conversion means for receiving the grouped data output from the reproducing conversion means and reconfiguring blocked data from the grouped data,
wherein the group conversion means includes:
block management data generation means for receiving the management data from the control means and generating block management data with respect to the corresponding blocked data, the block management data having a variable-length and containing information concerning each blocked data;
group management data generation means for receiving the management data and generating group management data containing information concerning the entire grouped data; and
grouped data generation means for receiving the blocked data, the block management data, and the group management data, and generating grouped data by arranging the blocked data, the block management data, and the group management data in a predetermined order.
In one embodiment of the present invention, the group reverse conversion means comprises:
group management data extraction means for extracting group management data from the grouped data;
block management data extraction means for extracting block management data from the grouped data and the extracted group management data;
block output control means for receiving the extracted block management data and group management data, determining the blocked data to be output based on the block management data and the group management data according to the control signal given by the control means, and generating a block output control signal designating the blocked data to be output; and
blocked data separating means for receiving the grouped data and the block output control signal and separating blocked data designated by the block output control signal from the grouped data, and outputting the separated blocked data.
Alternatively, the apparatus for recording and reproducing digital data of the present invention, comprises:
group conversion means for receiving input blocked data, arranging the blocked data in a predetermined order, and generating and outputting grouped data;
control means for receiving a command input together with the input blocked data and generating a control signal and management data based on the command;
recording conversion means for receiving the grouped data and converting the grouped data into a recording signal based on the control signal;
recording means for receiving the recording signal and recording data represented by the recording signal on a record medium;
reproducing means for reproducing from the record medium a signal representing the data recorded on the record medium;
reproducing conversion means for receiving the reproduced signal and converting the reproduced signal into grouped data; and
group reverse conversion means for receiving the grouped data output from the reproducing conversion means and reconfiguring blocked data from the grouped data,
wherein the group conversion means includes:
data transformation means for receiving the blocked data, data-transforming the blocked data, and generating recording blocked data;
block management data generation means for receiving the recording blocked data and the management data and generating block management data with respect to the corresponding recording blocked data, the block management data having a variable-length and containing information concerning the recording blocked data and the blocked data;
group management data generation means for receiving the recording blocked data and the management data and generating group management data containing information concerning the entire grouped data; and
grouped data generation means for receiving the recording blocked data, the block management data, and the group management data, and generating grouped data by arranging the recording blocked data, the block management data, and the group management data in a predetermined order.
In one embodiment of the present invention, the group reverse conversion means comprises:
group management data extraction means for extracting group management data from the grouped data;
block management data extraction means for extracting block management data from the grouped data and the extracted group management data;
block output control means for determining blocked data to be output and recording blocked data containing the blocked data to be output based on the extracted block management data and group management data in accordance with the control signal given by the control means, and generating a block output control signal designating the blocked data to be output, a block separating signal designating the recording blocked data related to the blocked data to be output, and an inverse transformation instructing signal instructing inverse transformation from the recording blocked data to the blocked data;
blocked data separation means for receiving the grouped data and the block separating signal, separating the recording blocked data designated by the block separating signal from the grouped data, and outputting the separated recording blocked data; and
data inverse transformation means for inverse-transforming the recording blocked data output from the blocked data separation means into the blocked data based on the inverse transformation instructing signal, and outputting the blocked data designated by the block output control signal.
In another embodiment of the present invention, the group conversion means formats so that each blocked data and the corresponding block management data are arranged adjacent to each other in each grouped data to be output.
In another embodiment of the present invention, the group conversion means arranges the group management data, the block management data, and the blocked data contained in each grouped data so that:
a leading edge of the group management data is placed in a predetermined position in the grouped data;
the blocked data are successively arranged from a leading edge of the grouped data, except for a portion where the group management data has been placed; and
the block management data are successively arranged after all of the arranged blocked data, except for a portion where the group management data has been placed, in accordance with an order in which the corresponding blocked data are arranged.
In another embodiment of the present invention, the group conversion means arranges the group management data, the block management data, and the blocked data contained in each grouped data so that:
a leading edge of the group management data is placed in a predetermined position in the grouped data;
the block management data are successively arranged from a leading edge of the grouped data, except for a portion where the group management data has been placed; and
the blocked data are successively arranged from a trailing edge of the grouped data, except for a portion where the group management data has been placed, in accordance with an order in which the corresponding block management data are arranged.
In another embodiment of the present invention, the group conversion means arranges the group management data, the block management data, and the blocked data contained in each grouped data so that:
a leading edge of the group management data is placed in a predetermined position in the grouped data;
the blocked data are successively arranged from a leading edge of the grouped data, except for a portion where the group management data has been placed; and
the block management data are successively arranged from a trailing edge of the grouped data, except for a portion where the group management data has been placed, in accordance with an order in which the corresponding blocked data are arranged.
In another embodiment of the present invention, the recording conversion means comprises:
first error-correction encoding means for performing error-correction encoding with respect to the grouped data;
searching data generation means for generating searching data based on management data given by the control circuit;
second error-correction encoding means for performing error-correction encoding with respect to the searching data; and
modulation means for modulating the error-corrected encoded grouped data and the error-corrected encoded searching data to generate the recording signal.
In another embodiment of the present invention, the reproducing conversion means comprises:
demodulation means for demodulating the reproducing signal to output the encoded grouped data and the encoded searching data;
first decoding means for receiving the encoded grouped data and performing error-correction decoding with respect to the encoded grouped data;
second decoding means for receiving the encoded searching data and performing error-correction decoding with respect to the received searching data; and
searching data generation means for extracting searching data of a group from the error-corrected decoded searching data.
In another embodiment of the present invention, the block management data generation means generates block management data corresponding to blocked data contained in one grouped data under a condition that specific different numbers are assigned to the respective block management data.
In another embodiment of the present invention, the block management data generation means generates block management data corresponding to blocked data contained in one grouped data under a condition that successive numbers are assigned to the respective block management data in an order in which the blocked data are input.
In another embodiment of the present invention, in a case where the grouped data contains the blocked data whose recording is started in the group, the searching data generation means generates, as the searching data, a number assigned to blocked data whose recording is first started among the blocked data,
in a case where the grouped data contains no blocked data whose recording is started in the group, the searching data generation means generates, as searching data, information indicating the absence of blocked data whose recording is started in the group.
In another embodiment of the present invention, the searching data generation means generates, as searching data, a number assigned to the blocked data which is first recorded in the grouped data, and information indicating whether or not the blocked data which is first recorded in the grouped data is recorded continuing from a preceding grouped data.
In another embodiment of the present invention, marks used for searching are input to the block management data generation means together with the blocked data, and the block management data generation means generates block management data for each mark, the block management data for each mark having a number indicating an order in which the marks are input.
In another embodiment of the present invention, in a case where the grouped data contains the marks whose recording is started in the group, the searching data generation means generates, as searching data, a number assigned to a mark whose recording is first started among the marks, in a case where the grouped data contains no marks whose recording is started in the group, the searching data generation means generates, as searching data, information indicating the absence of marks whose recording is started in the group.
In another embodiment of the present invention, the searching data generation means generates, as searching data, a number assigned to the mark which is first recorded in the grouped data, and information indicating whether or not the mark which is first recorded in the grouped data is recorded continuing from a preceding grouped data.
Alternatively, the apparatus for recording and reproducing digital data of the present invention, comprises:
group conversion means for receiving input blocked data, arranging the blocked data in a predetermined order to generate grouped data, and outputting the grouped data;
control means for receiving a command input together with the input blocked data and generating a control signal and management data based on the command;
recording conversion means for receiving the grouped data and converting the grouped data into a recording signal, including:
data track generation means for arranging the grouped data into data tracks;
preamble track generation means for generating preamble tracks arranged preceding the data tracks;
postamble track generation means for generating postamble tracks arranged following the data tracks; and
modulation means for receiving data arranged in track groups of the preamble tracks, the data tracks, and the postamble tracks, modulating the data arranged in track groups into a recording signal, and outputting the recording signal, recording means for receiving the recording signal and recording data represented by the recording signal on a record medium;
reproducing means for reproducing from the record medium a signal representing the data recorded on the record medium; and
postamble track detection means for detecting postamble tracks previously recorded on the record medium based on the reproduced signal and generating a detecting signal,
wherein the control means controls the recording conversion means based on the detecting signal, and making the recording conversion means start recording of the track groups in a position k tracks after a leading edge of the detected postamble tracks.
In one embodiment of the present invention, in a case where at least one successive grouped data is successively recorded,
the postamble track generation means generates postamble tracks only after data tracks in a last group of the successive grouped data, and
the preamble track generation means generates preamble tracks only before data tracks in a first group of the successive grouped data,
in a case where the successive grouped data is recorded after being divided into subgroups,
the postamble track generation means generates postamble tracks after data tracks of each subgroup, and
the preamble track generation means generates preamble tracks before data tracks of each subgroup.
In another embodiment of the present invention, in a case where at least one successive grouped data is successively recorded,
the postamble track generation means generates end data tracks as postamble tracks only after data tracks in a last group of the successive grouped data, and
the preamble track generation means generates preamble tracks only before data tracks in a first group of the successive grouped data,
in a case where the successive grouped data is recorded after being divided into subgroups,
the postamble track generation means generates end data tracks as postamble tracks after data tracks in a last subgroup among the subgroups, and generates postamble tracks different from the end data tracks after data tracks of the subgroups other than the last subgroup, and
the preamble track generation means generates preamble tracks before data tracks of each subgroup.
Alternatively, the apparatus for recording and reproducing digital data of the present invention, comprises:
group conversion means for receiving input blocked data, arranging the blocked data in a predetermined order to generate grouped data, and outputting the grouped data;
control means for receiving a command input together with the input blocked data and generating first management data and a control signal based on the command;
recording conversion means for receiving the grouped data output from the group conversion means and converting the grouped data into a recording signal based on the control signal;
recording means for receiving the recording signal and recording data represented by the recording signal on a record medium;
reproducing means for reproducing from the record medium a signal representing the data recorded on the record medium;
reproducing conversion means for converting the reproduced signal into grouped data; and
group reverse conversion means for receiving the grouped data output from the reproducing conversion means and reconfiguring blocked data from the grouped data,
wherein the control means generates a region control signal for setting at least one data region and management information region on the record medium, generates data region management information concerning the data region, with respect to each of the data region, generates record medium management information for managing the entire record medium, and generates a recording control signal for recording data in the data region and recording the record medium management information and the data region management information in the management information region.
In one embodiment of the present invention, the group conversion means comprises:
block management data generation means for receiving the management data from the control means and generating block management data with respect to the corresponding blocked data, the block management data having a variable-length and containing information concerning each blocked data;
group management data generation means for receiving the management data and generating group management data containing information concerning the entire grouped data; and
grouped data generation means for selectively receiving the blocked data, the block management data, and the group management data, and the record medium management information and the data region management information given by the control means, arranging the blocked data, the block management data, and the group management data in a predetermined order to generate first grouped data, arranging the record medium management information and the data region management information in a predetermined order to generate second grouped data, and outputting the first and second grouped data based on the region control signal.
In another embodiment of the present invention, the recording conversion means comprises:
error-correction encoding means for performing error-correction encoding with respect to the first and second grouped data, respectively; and modulation means for modulating the error-corrected encoded first and second grouped data to generate the recording signal, and outputs the recording signal based on the recording control signal.
In another embodiment of the present invention, the reproducing conversion means comprises:
demodulation means for demodulating the reproduced signal and outputting the encoded first and second grouped data; and
error-correction decoding means for receiving the encoded first and second grouped data and performing error-correction decoding with respect to the encoded first and second grouped data, respectively.
In another embodiment of the present invention, the group reverse conversion means comprises:
group management data extraction means for extracting group management data from the first grouped data;
block management data extraction means for extracting block management data from the first grouped data and the extracted group management data;
management information extraction means for extracting the record medium management information and the data region management information from the second grouped data;
block output control means for receiving the extracted block management data and group management data, determining the blocked data to be output based on the block management data and the group management data according to the control signal given by the control means, and generating a block control signal designating blocked data to be output; and
blocked data separation means for receiving the grouped data and the block output control signal, separating blocked data designated by the block output control signal from the grouped data, and outputting the separated blocked data.
In another embodiment of the present invention, the record medium is accommodated in a housing having an auxiliary record medium, and the control means controls the recording means to record the first grouped data on the record medium and records the second grouped data on the auxiliary record medium.
In another embodiment of the present invention, the record medium is accommodated in a housing having an auxiliary record medium, and the control means controls the recording means to record the data region management information among the first grouped data and the second grouped data on the record medium and records the record medium management information among the second grouped data on the auxiliary record medium.
In another embodiment of the present invention, the record medium is accommodated in a housing having an auxiliary record medium, and the control means controls the recording means to record part of the data region management information among the first grouped data and the second grouped data on the record medium and records the remaining part of the data region management information and the record medium management information among the second grouped data on the auxiliary record medium.
According to another aspect of the present invention, the-method for recording and reproducing digital data, comprises the steps of:
(a) arranging input blocked data in a predetermined order to generate grouped data;
(b) generating a control signal and management data based on a command input together with the input blocked data;
(c) converting the grouped data into a recording signal based on the control signal;
(d) recording data represented by the recording signal on a record medium;
(e) reproducing from the record medium a signal representing the data recorded in the record medium;
(f) converting the reproduced signal into grouped data; and
(g) reconfiguring blocked data from the grouped data,
wherein step (a) includes the steps of:
(a1) generating block management data for the corresponding blocked data based on the management data, the block management data having a variable-length and containing information concerning each blocked data;
(a2) generating group management data containing information concerning the entire grouped data based on the management data; and
(a3) generating grouped data by arranging the blocked data, the block management data, and the group management data in a predetermined order.
In one embodiment of the present invention, step (g) comprises the steps of:
(g1) extracting group management data from the grouped data;
(g2) extracting block management data from the grouped data and the extracted group management data;
(g3) determining the blocked data to be output based on the block management data and the group management data according to the control signal, and generating a block output control signal designating the blocked data to be output; and
(g4) separating blocked data designated by the block output control signal from the grouped data, and generating the separated blocked data to be output.
Alternatively, the method for recording and reproducing digital data of the present invention, comprises the steps of:
(a) arranging input blocked data in a predetermined order to generate grouped data;
(b) generating a control signal and management data based on a command input together with the input blocked data;
(c) converting the grouped data into a recording signal based on the control signal;
(d) recording data represented by the recording signal on a record medium;
(e) reproducing from the record medium a signal representing the data recorded on the record medium;
(f) converting the reproduced signal into grouped data; and
(g) reconfiguring blocked data from the grouped data,
wherein the step (a) includes the steps of:
(a1) transforming the blocked data and generating recording blocked data;
(a2) generating block management data for recording blocked data, the block management data having a variable-length and containing information concerning the recording blocked data and the blocked data;
(a3) generating group management data containing information concerning the entire grouped data based on the recording blocked data and the management data; and
(a4) generating grouped data by arranging the recording blocked data, the block management data, and the group management data in a predetermined order.
In one embodiment of the present invention, step (g) comprises the steps of:
(g1) extracting group management data from the grouped data;
(g2) extracting block management data from the grouped data and the extracted group management data;
(g3) determining blocked data to be output and recording blocked data containing the blocked data to be output based on the extracted block management data and group management data in accordance with the control signal, and generating block output control signal designating the blocked data to be output, a block separating signal designating the recording blocked data related to the blocked data to be output, and an inverse transformation instructing signal instructing inverse transformation from the recording blocked data to the blocked data;
(g4) separating the recording blocked data designated by the block separating signal from the grouped data, and generating the separated recording blocked data; and
(g5) inverse-transforming the recording blocked data into the blocked data based on the inverse transformation instructing signal, and generating the blocked data designated by the block output control signal.
In another embodiment of the present invention, in step (a), each blocked data and the corresponding block management data are arranged adjacent to each other in each grouped data.
In another embodiment of the present invention, in step (a), the group management data, the block management data, and the blocked data contained in each grouped data are arranged so that:
a leading edge of the group management data is placed in a predetermined position in the grouped data;
the blocked data are successively arranged from a leading edge of the grouped data, except for a portion where the group management data has been placed; and
the block management data are successively arranged after all of the arranged blocked data, except for a portion where the group management data has been placed, in accordance with an order in which the corresponding blocked data are arranged.
In another embodiment of the present invention, in step (a), the group management data, the block management data, and the blocked data contained in each grouped data are arranged so that:
a leading edge of the group management data is placed in a predetermined position in the grouped data;
the block management data are successively arranged from a leading edge of the grouped data, except for a portion where the group management data has been placed; and
the blocked data are successively arranged from a trailing edge of the grouped data, except for a portion where the group management data has been placed, in accordance with an order in which the corresponding block management data are arranged.
In another embodiment of the present invention, in step (a), the group management data, the block management data, and the blocked data contained in each grouped data are arranged so that:
a leading edge of the group management data is placed in a predetermined position in the grouped data;
the blocked data are successively arranged from a leading edge of the grouped data, except for a portion where the group management data has been placed; and
the block management data are successively arranged from a trailing edge of the grouped data, except for a portion where the group management data has been placed, in accordance with an order in which the corresponding blocked data are arranged.
In another embodiment of the present invention, step (c) comprises the steps of:
first error-correction encoding means for performing error-correction encoding with respect to the grouped data;
searching data generation means for generating searching data based on management data given by the control circuit;
second error-correction encoding means for performing error-correction encoding with respect to the searching data; and
modulation means for modulating the error-corrected encoded grouped data and the error-corrected encoded searching data to generate the recording signal.
In another embodiment of the present invention, step (f) comprises the steps of:
(f1) demodulating the reproducing signal to generate the encoded grouped data and the encoded searching data;
(f2) performing error-correction decoding with respect to the encoded grouped data;
(f3) performing error-correction decoding with respect to the encoded searching data; and
(f4) extracting searching data of a group from the error-corrected decoded searching data.
In another embodiment of the present invention, in step (a1), specific different numbers are assigned to the respective block management data.
In another embodiment of the present invention, in step (a1), successive numbers are assigned to the respective block management data in an order in which the blocked data are input.
In another embodiment of the present invention, in step (f1),
in a case where the grouped data contains the blocked data whose recording is started in the group, the searching data is generated to be a number assigned to blocked data whose recording is first started among the blocked data,
in a case where the grouped data contains no blocked data whose recording is started in the group, the searching data is generated to be information indicating the absence of blocked data whose recording is started in the group.
In another embodiment of the present invention, in step (f4), the searching data is generated to include a number assigned to the blocked data which is first recorded in the grouped data, and information indicating whether or not the blocked data which is first recorded in the grouped data is recorded continuing from a preceding grouped data.
In another embodiment of the present invention, step (a1) further comprises the step of generating block management data for marks, the marks being input together with the input blocked data, and the block management data for each mark having a number indicating an order in which the marks are input.
In another embodiment of the present invention, in step (f4),
in a case where the grouped data contains the marks whose recording is started in the group, the searching data is generated to be a number assigned to a mark whose recording is first started among the marks,
in a case where the grouped data contains no marks whose recording is started in the group, the searching data is generated to be information indicating the absence of marks whose recording is started in the group.
In another embodiment of the present invention, in step (f4), the searching data is generated to include a number assigned to the mark which is first recorded in the grouped data, and information indicating whether or not the mark which is first recorded in the grouped data is recorded continuing from a preceding grouped data.
Alternatively, the method for recording and reproducing digital data of the present invention, comprises the steps of:
(a) arranging input blocked data in a predetermined order to generate grouped data;
(b) generating a control signal and management data based on a command input together with the input blocked data;
(c) converting the grouped data into a recording signal, step (c) including:
(c1) arranging the grouped data into data tracks;
(c2) generating preamble tracks arranged preceding the data tracks;
(c3) generating postamble tracks arranged following the data tracks; and
(c4) modulating the data arranged in track groups of the preamble tracks, the data tracks, and the postamble tracks into a recording signal,
(d) recording data represented by the recording signal on a record medium;
(e) reproducing from the record medium a signal representing the data recorded on the record medium;
(f) detecting postamble tracks previously recorded on the record medium based on the reproduced signal and generating a detecting signal; and
(g) controlling the steps (c1) to (c4) based on the detecting signal, and making recording of the track groups start in a position k tracks after a leading edge of the detected postamble tracks.
In one embodiment of the present invention, in a case where at least one successive grouped data is successively recorded,
in step (c3), the postamble tracks are generated only after data tracks in a last group of the successive grouped data, and
in step (c2), the preamble tracks are generated only before data tracks in a first group of the successive grouped data,
in a case where the successive grouped data is recorded after being divided into subgroups,
in step (c3), the postamble tracks are generated after data tracks of each subgroup, and
in step (c2), the preamble tracks are generated before the data tracks of each subgroup.
In another embodiment of the present invention, in a case where at least one successive grouped data is successively recorded,
in step (c3), the end data tracks are generated as the postamble tracks only after data tracks in a last group of the successive grouped data, and
in step (c2), the preamble tracks are generated only before the data tracks in a first group of the successive grouped data,
in a case where the successive grouped data is recorded after being divided into subgroups,
in step (c3), end data tracks are generated as the postamble tracks after data tracks in a last subgroup among the subgroups, and postamble tracks which are different from the end data tracks are generated after the data tracks of the subgroups other than the last subgroup, and
in step (c2), the preamble tracks are generated before the data tracks of each subgroup.
Alternatively, the method for recording and reproducing digital data, comprises the steps of:
(a) arranging input blocked data in a predetermined order to generate grouped data, and outputting the grouped data;
(b) generating first management data and a control signal based on a command input together with the input blocked data;
(c) converting the grouped data into a recording signal based on the control signal;
(d) recording data represented by the recording signal on a record medium;
(e) reproducing from the record medium a signal representing the data recorded on the record medium;
(f) converting the reproduced signal into grouped data; and
(g) reconfiguring blocked data from the grouped data,
wherein step (b) includes the steps of;
(b1) generating a region control signal for setting at least one data region and management information region on the record medium,
(b2) generating data region management information concerning the data region, with respect to each of the data region,
(b3) generating record medium management information for managing the entire record medium, and
(b4) generating a recording control signal for recording data in the data region and recording the record medium management information and the data region management information in the management information region.
In one embodiment of the present invention, step (a) comprises the steps of:
(a1) generating block management data with respect to the corresponding blocked data, the block management data having a variable-length and containing information concerning each blocked data;
(a2) generating group management data containing information concerning the entire grouped data; and
(a3) arranging the blocked data, the block management data, and the group management data in a predetermined order to generate first grouped data,
(a4) arranging the record medium management information and the data region management information in a predetermined order to generate second grouped data, and
(a5) selectively outputting one of the first and second grouped data based on the region control signal.
In another embodiment of the present invention, step (c) comprises the steps of:
(c1) performing error-correction encoding with respect to the first and second grouped data; and
(c2) modulating the error-corrected encoded first and second grouped data to generate the recording signal based on the recording control signal.
In another embodiment of the present invention, step (f) comprises the steps of:
(f1) demodulating the reproduced signal to generate the encoded first and second grouped data; and
(f2) performing error-correction decoding with respect to the encoded first and second grouped data.
In another embodiment of the present invention, step (g) comprises the steps of:
(g1) extracting group management data from the first grouped data;
(g2) extracting block management data from the first grouped data and the extracted group management data;
(g3) extracting the record medium management information and the data region management information from the second grouped data;
(g4) determining the blocked data to be output based on the block management data and the group management data according to the control signal, and generating a block control signal designating blocked data to be output; and
(g5) separating blocked data designated by the block output control signal from the grouped data, and generating the separated blocked data.
In another embodiment of the present invention, the record medium is accommodated in a housing having an auxiliary record medium, step (e) comprises the step of (e1) recording data on the auxiliary record medium, and step (b) comprises step of controlling step (e1) to record the first grouped data on the record medium and to record the second grouped data on the auxiliary record medium.
In another embodiment of the present invention, the record medium is accommodated in a housing having an auxiliary record medium, step (e) comprises the step of (e1) recording data on the auxiliary record medium, and step (b) comprises the step of controlling step (e1) to record the data region management information among the first grouped data and the second grouped data on the record medium and to record the record medium management information among the second grouped data on the auxiliary record medium.
In another embodiment of the present invention, the record medium is accommodated in a housing having an auxiliary record medium, step (e) comprises the step of (e1) recording data on the auxiliary record medium, and step (b) comprises the step of controlling the step (e1) to record part of the data region management information among the first grouped data and the second grouped data on the record medium and to record the remaining part of the data region management information and the record medium management information among the second grouped data on the auxiliary record medium.
Thus, the invention described herein makes possible the advantage of providing an apparatus for recording and reproducing a digital signal, capable of recording data with efficiency and searching for data at a high velocity, and a method for the same.
This and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.